1. Field of the Invention
The present invention generally relates to an electrophoretic technique, and more particularly to an electrophoretic apparatus for forming an electrophoretic image by placing a substrate on which a sample has been applied in an electrophoretic vessel containing a buffer solution and conducting an electric current through the substrate.
2. Related Art Statement
Heretofore, there has been practiced an automatic chemical analyzer utilizing an electrophoresis. Such an analyzer has been used for analyzing biological high molecular substances such as various kinds of proteins contained in a serum sample. In the electrophoretic apparatus, after a sample serum has been applied on a substrate made of, for instance, cellulose acetate film wetted with a buffer solution, an electric current is flowed through the substrate while the substrate remains wet in an electrophoretic chamber containing the buffer solution to effect the electrophoresis. Then electrophoretic images of various kinds of components contained in the sample are formed on the substrate separately from each other. The electrophoretic images are visualized and the visible images are optically scanned by means of a densitometer and fraction images are operationally processed to effect a quantitative analysis for respective components in the sample.
In the electrophoretic apparatus mentioned above, the buffer solution contained in the electrophoretic chamber for keeping the substrate in the wetted condition is deteriorated due to fatigue. If the degree of fatigue of the buffer solution changes, the electrophoretic operation is varied and it is no longer possible to form the electrophoretic images precisely. Further the temperature of the buffer solution might be increased due to the supply of electric current and pH value and concetration of the buffer solution might be also varied. Due to these variations the electrophoretic images could not be obtained accurately and therefore there might be produced an analysis error. Under the above circumstances, in order to increase the analysis accuracy it is very important to detect the condition of the buffer solution in the electrophoretic chamber.
In the known electrophoretic apparatus, an operator judges the condition of the buffer solution by visually inspecting an expansion length and disturbances of the electrophoretic images formed on the substrate. Therefore, it is difficult to detect the condition of the buffer solution precisely and there is sometimes introduced a serious analysis error.